Discovery

Healthy people who have psychotic-like experiences also have decreased brain connectivity

Healthy people who have psychotic-like experiences also have decreased brain connectivity

18.10.2018

In a nutshell: Researchers have discovered a link between psychotic-like experiences in otherwise healthy individuals and disruption to their brain connectivity – which could be used to identify people at high risk of developing schizophrenia.

The human brain contains billions of nerve cells, which form networks – known as the human ‘connectome’ – that are important for healthy brain function. Aberrant connections in these networks can affect behaviour and cognition, and even lead to symptoms of psychosis such as hallucinations or delusions. Disorders such as schizophrenia are believed to arise as a result of abnormal brain connectivity.

In recent years, advances in neuroimaging techniques have enabled researchers to map the human connectome in more detail. Several studies have investigated its link to schizophrenia, showing that brain networks are disrupted and deteriorate as the illness progresses. However, only one study has looked at changes to the connectome in individuals who have had psychotic-like experiences but have not developed schizophrenia. It showed that they had subtle but detectable changes in their connectomes.

Brain Function CoE chief investigator Marta Garrido and colleagues Lena Oestreich and Roshini Randeniya from the Queensland Brain Institute conducted a similar study, but also assessed several other features of psychosis – such as depression and distress – that often appear before schizophrenia fully develops.

A group of healthy participants completed a comprehensive questionnaire about their psychotic-like experiences. They also underwent diffusion magnetic resonance imaging (MRI) of their brains, which the researchers used to estimate the connectivity between brain regions.

The researchers showed that participants with more psychotic-like experiences had weaker brain connectivity across the entire brain, similar to previous findings in schizophrenia.

The researchers’ discovery may help to identify individuals at high risk for developing schizophrenia, who might benefit from preventive treatments.

Next steps:The researchers are investigating whether structural and functional changes in brain connectivity can be used to predict psychotic-like experiences in healthy people.